The present invention relates to replaceable modules of a printing apparatus, and particularly to the monitoring of the performance and status of such replaceable modules in the printing apparatus.
Many machines have replaceable modules or subassemblies. Printing apparatus, for example, may have one or more replaceable modules, such as a fuser, a print cartridge, a toner cartridge, an electrostatic drum unit, etc. These subassemblies or modules may be individually replaceable by the user, or multiple of the assembly modules may be combined into a single customer replaceable module.
It is known to provide these replaceable modules with memory elements, such as electrically readable chips that, when the module is installed in a machine, enable the machine to read information from the memory and also to write information, such as a print count, to the module memory. The machine reads the information from the module memory element, and performs certain calculations to determine certain performance information, such as whether the replaceable module is due to be replaced. The machine updates the information in the memory element by writing to the memory element so that the machine can continue to monitor the status of the replaceable module.